Multi-protocol receiver

ABSTRACT

A multi-protocol receiver system for receiving wireless communications. The system comprises programmable stages for controlling each steps of the demodulation of at least one broadband signal to provide the I and Q signals of at least one specific frequency narrow band for further processing. The receiver can be used in a software defined radio system.

FIELD OF THE INVENTION

The present invention relates to wireless receivers. More precisely,this invention describes a multi-protocol receiver for intercepting,monitoring and/or recording conversation over a cellular network.

BACKGROUND OF THE INVENTION

With the increasing complexity of telecommunication means, criminals arefinding new ways to escape from the surveillance of the police or otherlaw enforcement agencies. This can, potentially, become a threat tosociety. More specifically this problem is increasing with the globaldevelopment of mobile telecommunication means.

The term mobile telecommunication can include technologies ranging fromcordless telephones, digital cellular mobile radios, and personalcommunication systems that are evolving to wireless data and networks.

A mobile telecommunication system is usually composed of a base station13, connected to the public telephone network via a Mobile TelephoneSwitching Office (MTSO), and of a group of mobile users 14. The basestation 13 covers a certain geographical area.

A communication between a mobile user and a standard public network useris thus performed using the base station 13. Each communication linkuses a particular frequency band known as a voice channel. The uplinktransmission refers to the signal sent by a mobile station 14 to a basestation 13, while the downlink transmission refers to a signal sent bythe base station 13 to a mobile station 14. Therefore, a singleconversation requires two voice channels. The monitoring of a particularconversation implicitly requires the monitoring of the two voicechannels. One prior technique for monitoring cellular telephoneconversations involves a simple tuner that scans voice channels. Thistechnique is not efficient when the number of communications to handleis high and when the frequency of the voice channel changes often.

A second technique consists of monitoring the two voice channels and thetraffic channels of the communication system in order to handle thehandover (i.e. when a user, by a physical displacement, changes basestations). Thus it is possible to track a user through a cellularnetwork.

Focusing more precisely on wide band receivers, the prior art comprisesone type of system which is composed of a group of front end radiofrequency demodulation stages which include parallel narrow-bandreceivers. Usually, the Radio Frequency (RF) band coverage provided bythese narrow-band receivers is of adjacent frequency. Each RF stage hasits own local oscillator frequency and Intermediate Frequency (IF)stages. Such a system is very costly because only one RF stage isworking at a time. The inactive RF stages are superfluous duringoperations.

In another configuration (described in patent U.S. Pat. No. 6,002,924col 1, line 57 to 67), the choice of the first IF and the first localoscillator, the second IF and the second local oscillator allow the userto access a broad band radio receiver. However, because ofinter-modulation and image frequency response, certain frequencies arenot available. This element is unacceptable for the purpose of this use.

In U.S. Pat. No. 6,002,924, Takano succeeds to create a broadband radioreceiver with a continuous spectrum. However, there is still a gap tofill in order to complete the task of intercepting users because foreach voice interception, two receivers are needed; this is too costlytherefore this is not acceptable. Furthermore, the processing of the RFsignal is completed using an analog processing. This analog receiverarchitecture has the serious drawback to use multiple mixers andfilters. Furthermore, the analog receiver architecture is subject totemperature drift and mismatch from part variations.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide an efficientarchitecture that will avoid one or more of the shortcomings of theconventional technology.

It is an object of the present invention to provide a scanner for mobiletelecommunications.

It is an object of the present invention to provide a scanner for mobilecommunications that will be able to handle simultaneously a consequentnumber of conversations coming from any part of the available frequencybands.

Another object of the present invention is to provide a scanner thatwill be able to cope with various frequency bands.

Another object of the present invention is to provide a scanner thatwill be able to cope with various telecommunications protocols.

Yet another object of the present invention is to provide a receiverthat can be software controlled.

Yet another object of the present invention is to provide a scanner inwhich there is a possibility to achieve a protocol upgrade of thesystem.

Yet another object of the present invention is to provide a scanner inwhich there is a possibility to achieve a frequency band update of thesystem.

Yet another object of the invention is to provide a scanner in whichthere is a possibility to add other users to the system.

According to one aspect of the invention, there is provided a method forscanning a group of mobile telecommunication users. The methodcomprising the steps of: collecting a wideband frequency signal using anantenna, performing a first demodulation of the wideband frequencysignal to obtain a demodulated wide band signal; digitizing thedemodulated signal to obtain a digital demodulated signal; routing thedigital demodulated signal to a device which performs on the digitaldemodulated signal a narrowband extraction, performing the narrow bandextraction on the digital demodulated signal and generating an in-phasecomponent and a quadrature component for a selected voice channel.

In accordance with another aspect of the present invention, there isprovided an apparatus for monitoring the communications of a group ofmobile users. The apparatus first comprises at least one demodulationunit, also called RF receiver unit, a number of demodulation unitsdepending on a number of different frequency bands that are targeted tobe monitored. Each demodulation unit is composed of two separatecircuits that are each dedicated to the scanning of a downlinktransmission and an uplink transmission. The apparatus also comprises anAnalog to Digital Converter (ADC) whose goal is to convert the analogsignal into a digital signal. The apparatus also comprises a CentralProcessing Unit (CPU), which routes the signal through the Digital DownConverters (DDC) and commands the demodulation unit. The narrow bandextraction is performed at this stage. Finite Input Response (FIR)filtering is also performed. The output signal can be decoded by aprocessing unit in accordance with the protocol that was used to encodethe information.

According to another aspect of the invention, there is provided a methodfor tracking a mobile. The method comprising the steps of: requestingfrom a user at least one wireless conversation to monitor, receiving atleast one control channel signals using a control channel receiver,processing said received control channel signals according to at leastone of said wireless conversations to monitor to provide at least onevoice channel, each one of said voice channels corresponding to onewireless conversations to monitor, storing in a memory a relationbetween one of said wireless conversations to monitor and one of saidvoice corresponding voice channel, setting, using pre-recorded data onthe type of wireless telecommunication protocol and frequency bandcoming from a non-volatile memory, the parameters of the filters, thefrequency of the down converters, and the paths in the switch in orderto track said users.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be better understood by an examination of thefollowing description, together with the accompanying drawings, inwhich:

FIG. 1 shows an overview of a base station and mobile unit widebandscanner;

FIG. 2 shows the RF stage and the processing unit, the RF stagecomprises four RF units; the system depicted there can process fourdifferent full duplex conversations coming from four different frequencybands;

FIG. 3 shows the RF unit that can process a full duplex wirelessconversation;

FIG. 4 shows a DDC unit and a filter stage that can process a fullduplex wireless conversation;

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

While the present invention may be provided in various embodiments,there is shown in the drawings and described in the following text aspecific preferred embodiment, with the understanding that the presentdescription is only one embodiment and is not limiting of scope of theinvention.

FIG. 1 presents one embodiment of the invention. The system in thepreferred embodiment is a scanner, that is a device which monitorstransmission from either a base station 13 or a mobile 14. Such a deviceis used typically by police for lawful intercept of cellulartelecommunications. An antenna 10 collects the radio signals coming fromthe base unit 13 and the mobile unit 14. A demodulation unit 11 handlesradio signals. The demodulation unit 11 provides the IF signal to theprocessing unit 12. The RF unit 11 imposes limitations on this signal inorder to prevent it from being harmful for the following stages. Theprocessing unit 12 is able to select parts of the wideband signal comingfrom either a base unit 13 or a mobile unit 14. A management unit 15controls the processing unit 12 and get signals from the RF unit 11. Ina preferred embodiment, the management unit 15 comprises a computer witha data acquisition hardware and a software.

FIG. 2 shows the different parts of the architecture of the system inthe preferred embodiment.

Each unit 16, composed of a RF stage 11 and an ADC stage 21, is capableto collect the base station signal and the mobile station signal of acertain frequency band. In the preferred embodiment, the scanner is ableto tap simultaneously four different frequency bands because the deviceis composed of four units 16. Each RF unit 11 sends a power informationsignal 33 to the management unit 15. The ADC stage 21 is connected to arouter 22 that is, in the preferred embodiment, a Field ProgrammableGate Array (FPGA). The router 22 is controlled by the management unit 15using signal 36. Next to the router unit 22, a group of DDC units 23 areconnected via a bus 28. Finally a filter stage 24 is connected to eachDDC unit 23 using signals 29 and 30. This filter stage 24 is controlledby the management unit 15 using signal 35. The filter stage 24 providesignals 31 and 32 to the demodulation units. The demodulation units arenot shown in FIG. 2, and may comprise standard demodulation circuits forextracting information from the regular bandwidth signal according tothe wireless transmission protocol of each regular bandwidth signal,e.g. TDMA, AMPS, GSM.

The antenna 10 receives the radio signal. Typically, the signal powerranges between −110 dBm and −14 dBm.

In the case of a cellular system, the frequency band is located between824 MHz and 894 MHz. The uplink band is located between 824 MHz and 849MHz, while the frequency band located between 869 MHz and 894 MHz isdedicated for downlink communications.

In the case of a Personal Communication Service (PCS) system, thefrequency band is located between 1850 MHz and 1990 MHz. The uplinkfrequency band is located between 1850 MHz and 1910 MHz, while thedownlink frequency band ranges from 1930 MHz and 1990 MHz. The downlinkfrequency band is shared into two frequency bands: the low downlinkfrequency band which is located between 1930 MHz and 1960 MHz, and thehigh downlink frequency band which is located between 1960 MHz and 1990MHz. The uplink frequency band is shared into two frequency bands: thelow uplink frequency band which is located between 1850 MHz and 1880MHz, and the high uplink frequency band which is located between 1880MHz and 1910 MHz.

The RF unit 11, described in FIG. 3, filters and amplifies the incomingsignal 20, collected by the antenna 10. More precisely, a duplexerdivides the signal 20 into two different signals 80 and 81,corresponding to the downlink and the uplink transmission. Thus, theseseparated signals 80 and 81 can be sent to two different parts: a mobileRF stage (which comprises elements: 61, 62, 63, 64, 65, 66, 67, 68, 69)and a base RF stage (which comprises elements: 51, 52, 53, 54, 55, 56,57, 58, 59). These two different stages allow the scanning of either theradio signals coming from the mobile unit 14 or the radio signals comingfrom the base unit 13.

In both cases, the signal collected by the antenna 10 is filtered byfilter. In the case of a base station signal, the filter is filter 51which will only select frequency signals located between 869 and 894 MHzin the case of a cellular system. In the case of a PCS system, filter 51only selects frequency signals located between either 1930 MHz and 1960MHz (low part of the base station signal) or 1960 MHz and 1990 MHz (highpart of the base station signal).

In the case of a mobile station signal, the filter 61 only selectsfrequency signals located between 824 MHz and 849 MHz in the case of acellular system. In the case of a PCS system, filter 61 only selectsfrequency signals located between either 1850 MHz and 1880 MHz (low partof the mobile signal) or 1880 MHz and 1910 MHz (high part of the mobilesignal).

In the case of a base station signal, a RF amplifier 52 amplifies signal82 coming from the frequency filter 51. In the case of a mobile signal,the RF amplifier 62 amplifies signal 92 coming from the frequency filter61.

In the preferred embodiment, and in the case of a cellular system, thelocal oscillator 53 comprises an ultra low noise TCXO local oscillatorfollowed with a signal amplifier, a frequency multiplier, by a factor of2, a signal amplifier, frequency multiplier, by a factor of 2, a signalamplifier, a frequency multiplier, by a factor of 2, an amplifier, anharmonic filter and an amplifier. The harmonic filter is a bandpassfilter that will reject non desired harmonics.

In the case of the cellular system, the frequency of the ultra low noiseTCXO local oscillator is 117 MHz. Thus, the oscillator 53 generates asignal 84 with a frequency of 936 MHz. In the case of the cellularsystem, the local oscillator 53 calibrated at 936 MHz, is connected to amixer 54. Such a system will translate the signal from a centralfrequency of 881.5 MHz down to a central frequency of 54.5 MHz, that hasbeen chosen in order to be compatible with the central frequency of thefollowing filter 55. The bandwidth will remain 25 MHz.

In the case of a PCS low-band base station signal, the frequency of theultra low noise TCXO local oscillator is 118.125 MHz. The ultra lownoise TCXO local oscillator is followed by a signal amplifier, afrequency multiplier, by a factor of 2, a signal amplifier, a frequencymultiplier, by a factor of 2, a signal amplifier, frequency multiplier,by a factor of 2, a signal amplifier, a frequency multiplier, by afactor of 2, an amplifier, an harmonic filter and an amplifier. Thus,the oscillator 53 generates a signal 84 with a frequency of 1890 MHz. Inthe case of a PCS low-band base station signal, the local oscillator 53calibrated at 1890 MHz is connected to a mixer 54. Such a system willtranslate the signal from a central frequency of 1945 MHz down to acentral frequency of 55 MHz, that has been chosen in order to becompatible with the central frequency of the following filter 55. Thebandwidth will remain 30 MHz.

In the case of a PCS high-band base station signal, the frequency of theultra low noise TCXO local oscillator is 120 MHz. The ultra low noiseTCXO local oscillator is followed by a signal amplifier, a frequencymultiplier, by a factor of 2, a signal amplifier, a frequencymultiplier, by a factor of 2, a signal amplifier, a frequencymultiplier, by a factor of 2, a signal amplifier, a frequencymultiplier, by a factor of 2, an amplifier, an harmonic filter and anamplifier. Thus, the oscillator 53 generates a signal 84 with afrequency of 1920 MHz. In the case of a PCS high-band base stationsignal, the local oscillator 53 calibrated at 1920 MHz is connected to amixer 54. Such a system will translate the signal from a centralfrequency of 1975 MHz down to a central frequency of 55 MHz, that hasbeen chosen in order to be compatible with the central frequency of thefollowing filter 55. The bandwidth will remain 30 MHz.

A local oscillator 63, in the case of a mobile signal, is connected to amixer 64. In the preferred embodiment, and in the case of the cellularsystem, the local oscillator 63 comprises an ultra low noise TCXO localoscillator followed with a signal amplifier, a frequency multiplier, bya factor of 2, a signal amplifier, a frequency multiplier, by a factorof 2, a signal amplifier, a frequency multiplier, by a factor of 2, anamplifier, an harmonic filter and an amplifier. The harmonic filter is abandpass filter that will reject non desired harmonics.

In the case of the cellular system, the frequency of the ultra low noiseTCXO local oscillator is 97.75 MHz. Thus, the oscillator 63 generates asignal 94 with a frequency of 782 MHz. In the case of a mobile cellularfrequency band, the local oscillator 63 calibrated at 782 MHz isconnected to a mixer 64. Such a system will translate the signal from acentral frequency of 836.5 MHz down to a central frequency of 54.5 MHz,that has been chosen in order to be compatible with the centralfrequency of the following filter 65. The bandwidth will remain 25 MHz.

In the case of a PCS low-band mobile station signal, the frequency ofthe ultra low noise TCXO local oscillator is 120 MHz. The ultra lownoise TCXO local oscillator is followed by a signal amplifier, afrequency multiplier, by a factor of 2, a signal amplifier, a frequencymultiplier, by a factor of 2, a signal amplifier, a frequencymultiplier, by a factor of 2, a signal amplifier, a frequencymultiplier, by a factor of 2, an amplifier, an harmonic filter and anamplifier. Thus, the oscillator 63 generates a signal 94 with afrequency of 1920 MHz.

In the case of a PCS low-band mobile station signal, the localoscillator 63 calibrated at 1920 MHz is connected to a mixer 64. Such asystem will translate the signal from a central frequency of 1865 MHzdown to a central frequency of 55 MHz, that has been chosen in order tobe compatible with the central frequency of the following filter 65. Thebandwidth will remain 30 MHz.

In the case of a PCS high-band mobile station signal, the frequency ofthe ultra low noise TCXO local oscillator is 121.875 MHz. The ultra lownoise TCXO local oscillator is followed by a signal amplifier, afrequency multiplier, by a factor of 2, a signal amplifier, a frequencymultiplier, by a factor of 2, a signal amplifier, a frequencymultiplier, by a factor of 2, a signal amplifier, a frequencymultiplier, by a factor of 2, an amplifier, an harmonic filter and anamplifier. Thus, the oscillator 63 generates a signal 94 with afrequency of 1950 MHz. In the case of a PCS high-band mobile stationsignal, the local oscillator 63 calibrated at 1950 MHz is connected to amixer 64. Such a system will translate the signal from a centralfrequency of 1895 MHz down to a central frequency of 55 MHz, that hasbeen chosen in order to be compatible with the central frequency of thefollowing filter 65. The bandwidth will remain 30 MHz.

In all cases, and in the preferred embodiment, the multiplication of thesignals provided by the mixer is completed with a high S/N ratio.

In the case of a base cellular signal, a filter 55, with a centralfrequency of 54.5 MHz only selects the desirable bandwidth, i.e. 25 MHz,of the incoming signal 85. In the case of a PCS base signal, the filter55, with a central frequency of 55 MHz, will only select the desirablebandwidth, i.e. 30 MHz, of the incoming signal 85.

In the case of a mobile cellular signal, a filter 65, with a centralfrequency of 54.5 MHz only selects the desirable bandwidth, i.e. 25 MHz,of the incoming signal 95

In the case of a PCS mobile signal, the filter 65, with a centralfrequency of 55 MHz, will only select the desirable bandwidth, i.e. 30MHz, of the incoming signal 95.

In the case of a base signal, an IF amplifier 58 boosts the selectedsignal 86 after filter 55. In the case of a mobile signal, an IFamplifier 68 boosts the selected signal 96 after filter 65.

In both cases, the amplification of the signal can be chosen between 14dB and 56 dB by a gain controller 60. The amplification is performedwith a high S/N ratio. The objective of the RF stage 11 is to get anoutput power of 0 dBm at the end of the RF stage 11.

In the case of a base signal, amplifier 58 is connected to a limitationcircuit 56 via signal 87. The limitation circuit 56, which is composedof diodes, protects the end of the RF stage 11 from voltage peaks thatwould be harmful to the following stages.

A filter 57 is connected to the limitation circuit 56 using signal 88.The filter 57 is composed of resistances and capacitors. The filter 57is connected to a detection circuit 59 which converts the output signal89 into a DC value comprised between 0 and 2.5 V, and proportionate tothe output power of signal 89. The DC value is then used as a feedbackreference in order to control the IF amplifiers 58 and to provide anoutput power signal closed to 0 dBm. The gain controller 60, thatcollects the feedback signal 91 comprises, in the preferred embodiment,a PIC 16C74 processor. In the preferred embodiment, the gain controller60 adjusts the gain of amplifiers 58 and 68 each 46 msec. The gaincontroller 60 also comprises, in the preferred embodiment, an EEPROMwhich stores the relation between voltage signal and power in dBm. Theoutput power computed by the gain controller 60 using signal 91 and 101is transmitted to the management unit 15. In the preferred embodiment,the transmission is completed using a RS232 interface.

In the case of a mobile signal, the amplifier 68 is connected to alimitation circuit 66 via signal 97. The limitation circuit 66, which iscomposed of diodes, protects the end of the RF stage 11 from voltagepeaks that would be harmful to the following stages.

A filter 67 is connected to the limitation circuit 66 using signal 98.The filter 67 is composed of resistances and capacitors. The filter 67is connected to a detection circuit 69 which converts the output signal99 into a DC value comprised between 0 and 2.5 V, and proportionate tothe output power. The DC value is then used as a feedback reference inorder to control the IF amplifiers 68, using the gain controller 60, andto provide an output power signal closed to 0 dBm.

Referring to FIG. 2, an ADC stage 21 follows the RF stage 11. The ADCstage 21 converts signals 89 and 99. The conversion is performed at arate of 75 MHz, thus it more than satisfies Nyquist sampling theorem forthe 25 MHz signal. The quantization is 10 bits. It is important tonotice that the device used for the analog to digital conversion has ahigh Signal/noise (S/N) ratio in the preferred embodiment. After theconversion, the information becomes a flow of digital information. Arouter 22, that is, in the preferred embodiment a FPGA, will then routethis flow of information through the DDC 23. The router acts as a switchwhich performs path selection between multiple parts. The choice of aFPGA is justified by the fact that it can be soft-configured veryeasily, and by the fact that it can handle very large amount of data (ithas a large bandwidth). The router 22 is controlled by the managementunit 15. The router 22 creates a data bus 28 that is connected to theDDC 23. Each DDC 23 is then able to collect data coming from aparticular unit 16. The DDC 23 is a tuneable down converter adapted tonumerical signals.

Each DDC 23 downconverts the signal 28 with a local oscillator and anin-phase and quadrature downconverter. The management unit 15 controlsthe DDC 23 and allows each DDC 23 to select a specific conversation.

FIG. 4 describes more precisely the operations completed by the DDC 23.

In the preferred embodiment, the DDC 23 is an Intersil HSP50016. Thegoal of the DDC 23 is to extract a narrow frequency band of interestfrom a wideband input signal, convert that band to a baseband and outputit in either a quadrature or a real form. In the present invention, thegoal of each DDC is to select a voice channel coming either from thebase station 13 or from the mobile unit 14 via the router 22, in orderto intercept it.

The narrow band extraction is performed by down converting and centeringthe band of interest. The DDC 23 has an input data stream of 16 bits inwidth and 75 MSPS in data rate. As the ADC 21 performs the conversionwith a quantization of only 10 bits, the six (6) Less Significant Bit(LSB) are grounded in order to maintain a good accuracy. The conversionis done by multiplying the input data 28 with a quadrature sinusoidgenerated by a complex sinusoid generator 110. In order to get thein-phase component (designated as I) 29 of the quadrature sinusoid, thesignal 28 is multiplied by a cosine signal 130 in the mixer 111. Inorder to get the quadrature component (designated as Q) 30, the signal28 is multiplied by a sine signal 135 in the mixer 120. The frequency ofthe complex sinusoid generator 110 of the DDC 23 can be selected by themanagement unit 15 in order to select a specific voice signal.

A quadrature lowpass filter 114 is applied to the output of the mixer111. Another quadrature lowpass filter 123 of the same type of the aboveis connected to the output of the mixer 120. In the preferredembodiment, filtering chain 114 consists of a cascaded High DecimationFilter (HDF) 112 and a low pass FIR filter 113. The filtering chain 123,in a preferred embodiment, consists of a cascaded HDF 121 and a low passFIR filter 122. The combined response of the two stages filters resultsin a −3 dB to −102 dB shape factor. Each filtering chain (114 and 123)is controlled by the management unit 15 according to the voice channelselected. The decimation factor is 4×78 in the case of AMPS. Thedecimation factor is 4×77 in the case of DAMPS.

Each DDC 23 provides the quadrature signal (Q) 30 and the in-phasecomponent (I) signal 29 of a specific voice channel to tap. The outputfrequency of signal I 29 and signal Q 30 is 240.384 kHz in the case ofAMPS. In the case of DAMPS, the output frequency of signal I 29 andsignal Q 30 is 243.506 kHz.

The signals 29 and 30 are filtered through a FIR 24. In the preferredembodiment, FIR 24 is a HSP43124SC-33 which is programmable. The FIRfilter 24 is controlled by the management unit 15 which provides thecoefficients for the right protocol.

In the case of AMPS and in the preferred embodiment, the algorithm ofParks-McClellan is used to compute the coefficients of the order 233 FIR24. The algorithm of Parks-McClellan is also used to compute thecoefficients of the order 233 FIR 24 in the case of DAMPS. In the caseof GSM and CDMA, a similar approach is used to compute the coefficientsof the FIR 24. In the preferred embodiment, the low pass frequency ofthe filter FIR 24 is 12.4 kHz; and the attenuation is 80 dB at 17.6 kHzin the case of AMPS and DAMPS.

The signals 31 and 32 are available for demodulation according to theprotocol used for the transmission.

1. A multi-protocol receiver for receiving wireless transmissionscomprising: a plurality of RF receiver units each receiving a wirelesssignal and outputting a broadband IF signal; a plurality of tunable downconverter units, each able to tune over a frequency range of all of saidbroadband IF signal of all of said RF receiver units, and said pluralityof tunable down converter units output raw I and Q signals; a pluralityof tunable filters receiving said raw I and Q signals from one of saidplurality of tunable down converter units and providing filtered I and Qoutput signals; a switch for coupling a selected RF receiver unit ofsaid plurality of RF receiver units to a selected one of said pluralityof tunable down converter units; and a management unit receiving arequest for a specific frequency band and setting a tuning frequency ofa selected one of said plurality of tunable down converter units,setting filter parameters of a selected one of said plurality of tunablefilters, and setting said switch.
 2. The multi-protocol receiver asclaimed in claim 1, further comprising a plurality of ADC units eachconnected to one of said plurality of RF receiver units, wherein saidswitch connects a broadband digital output of said plurality of ADCunits to said plurality of tunable down converter units.
 3. Themulti-protocol receiver as claimed in claim 2, wherein the managementunit comprises: a channel selection signal input; a memory for storingsaid filter parameters for channels from said broadband IF signal of allof said RF receiver units and frequency parameters for all of saidtunable down converter units and switch parameters; an interpreterreceiving said selection signal and setting said filter parameters, saidtunable down converters, and said switch parameters based on data storedin said memory.
 4. The multi-protocol receiver as claimed in claim 3,wherein there are at least two of said tunable down converter units inorder to receive full duplex conversations, said memory for storingswitch parameters provides information for allocating said at least twoof said tunable down converter units to said full duplex conversations.5. The multi-protocol receiver as claimed in claim 2, wherein there areat least two of said tunable down converter units in order to receivefull duplex conversations.
 6. The multi-protocol receiver as claimed inclaim 2, wherein a tunable filter of said plurality of tunable filtersis an N tap FIR filter.
 7. The multi-protocol receiver as claimed inclaim 2, wherein said switch is an FPGA.
 8. The multi-protocol receiveras claimed in claim 2, wherein each of said ADC units performs theconversion at a rate of at least 50 MHz.
 9. The multi-protocol receiveras claimed in claim 1, wherein the management unit comprises: a channelselection signal input; a memory for storing said filter parameters forchannels from said broadband IF signal of all of said RF receiver unitsand frequency parameters for all of said tunable down converter unitsand switch parameters; an interpreter receiving a selection signal andsetting said filter parameters, said tunable down converters, and saidswitch parameters based on data stored in said memory.
 10. Themanagement unit as claimed in claim 9, wherein the interpreter is aDigital Signal Processor (DSP).
 11. The multi-protocol receiver asclaimed in claim 1, wherein there are at least two of said tunable downconverter units in order to receive full duplex conversations.
 12. Themulti-protocol receiver as claimed in claim 1, wherein a plurality ofsaid RF receiver units, each receives a portion of a single frequencyband.
 13. The multi-protocol receiver as claimed in claim 1, wherein asingle frequency band, larger than one handled by a single one of saidRF receiver unit, is handled by a plurality of said RF receiver units.14. The multi-protocol receiver as claimed in claim 1, wherein each ofsaid RF receiver units handles at least 25 MHz bandwidth signal.
 15. Amethod for receiving a wireless communication with a device whichcomprises a plurality of RF receiver units, a plurality of tunable downconverter units, a plurality of tunable filters, a switch and comprisingthe steps of: receiving a request for a specific frequency band andsetting a tuning frequency of a selected one of said plurality oftunable down converter units; setting filter parameters of a selectedone of said plurality of tunable filters; setting said switch in orderto couple one of said plurality of RF receiver units to one of saidplurality of tunable down converter units; receiving a wireless signalfrom an antenna and outputting an IF broadband signal; down convertingthe IF broadband signal to provide raw I and Q signals; and filteringthe raw I and Q signals to provide filtered I and Q signals.
 16. Amethod as claimed in claim 15 additionally comprising the step of:digitizing said IF broadband signal by an ADC unit before saidswitching.
 17. A method as claimed in claim 16, wherein the step ofswitching said switch is directed by a management unit.
 18. A method asclaimed in claim 15, wherein the step of switching said switch isdirected by a management unit.